WO2000006667A2 - Method and installation for the pyrolysis of waste products containing hydrocarbons - Google Patents

Abstract

The invention relates to a method and an installation for the pyrolysis of waste products containing hydrocarbons, notably used tires or biological waste, according to which the material to be pyrolyzed is introduced into a pyrolysis furnace and pyrolyzed at 500 °C. An essential feature is that the material, preferably in whole pieces, is placed outside the furnace (1) into a receiving device which is introduced into the pyrolysis furnace, which is open at the bottom, from below, such that said receiving device tightly seals the furnace (1). An essential advantage is that several different receiving devices can be made available for different types of material so that the pyrolysis installation can be used for different pyrolysis materials in relatively rapid rotation, without the need to makes changes to the furnace.

Description

 DESCRIPTION

METHOD AND SYSTEM FOR PYROLYZING HYDROCARBON

SUSTAINABLE WASTE PRODUCTS

The invention relates to a method and a plant for the pyrolysis of hydrocarbonaceous material, in particular used tires, thereby ensuring an economical and environmentally friendly use of organic waste, such as used tires, plastics, paper, biomass, such as agricultural and forest waste.

A variety of methods and devices or systems are known with which reusable materials, in particular fuels, can be provided by pyrolysis from waste. All of these methods and systems have the common disadvantage that they are either extremely complex to build and operate and, moreover, can only be used for the same type of material.

For example, known from DE 26 58 371 C2, DE 35 45 954 AI and DE 35 23 653 C2 fluidized bed reactors in which large-scale material, e.g. Uncrushed or only roughly shredded old tires are introduced into the furnace from above and pyrolyzed, while the gaseous substances are drawn off upwards and the solids are discharged downwards. The structure of these devices is relatively complex and by using a sand and cement clinker bed, with a correspondingly radially introduced fluidizing gas, maintaining the corresponding flow conditions in the fluidized bed is often problematic and can be caused by

CONFIRMAΠON COPY introduced material mass can be easily brought out of balance. These systems cannot be used for smaller, flexible embodiments that can be easily converted to different pyrolysis materials.

Furthermore, so-called pyrolysis continuous furnaces or fluidized bed furnaces are known in which the pyrolysis material is either pyrolyzed in whole pieces or comminuted, e.g. described in DE 44 47 357 AI, DE 29 25 202 AI, DT 25 20 754 AI and DE 26 39 165 AI. These pyrolysis continuous furnaces also have an extremely complex design, are each designed for a certain type of material and / or size and cannot be easily converted to different types of material.

Pyrolysis plants are also known, e.g. from DE 27 24 813 AI, EP 0 477 187 B1 and DE 30 30 593 C2, by means of which crushed used tires or other organic waste are pyrolyzed. These plants are partly complex and can also not be used as an alternative, without special modification, both for entire old tires and for piece or bulk material.

Finally, DE 31 38 128 C2 discloses a process for the thermal conversion of old tires into liquid and gaseous substances, in which a trolley loaded with old tires is inserted horizontally into an oven. The tires are treated with oil heated to approx. 390 ° using the trickle technique.

The object of the invention is therefore a method and a To specify the system of the type mentioned above, which are simple to carry out or which have a simple structure and which allow any rapid change in relation to the material to be pyrolyzed, for example from whole old tires to organic bulk waste material, without any special refitting of the furnace itself.

This object is achieved according to the invention by a generic method or an installation with the features of claims 1 and 7, respectively. Advantageous further developments are given in the corresponding back-related subclaims.

Accordingly, the material to be pyrolyzed is introduced vertically from below into a substantially bell-shaped pyrolysis furnace which can be revealed at the bottom with the aid of a corresponding receiving device and pyrolyzed at approximately 500 ° C., the volatile constituents (carbonization gas) possibly being cleaned in a known manner and passed into a condenser become. Depending on the process control, different gaseous and liquid constituents are obtained, for example oil, which can be used, inter alia, as heating oil. This heating oil can be used to operate the burner of the pyrolysis furnace according to the invention, so that no additional external energy is required to operate the system, at least the pyrolysis furnace. The solid residues remaining after the pyrolysis, such as steel wire scrap and pyrolysis carbon, are moved out of the furnace vertically downward after the pyrolysis in or with the holding device and brought into an unloading station and removed there from the holding device. Depending on what is to be pyrolyzed for a hydrocarbonaceous material, such as uncrushed old tires of different sizes, shredded plastic parts or bio-waste material such as wood, straw, green plants, herbs, etc., the materials are to be introduced according to the invention in principle in different recording devices.

In this way, old tires are introduced into holding devices which have one, three or more vertically pointing, fixed holding rods on a base plate, on which the tires are each lined up or stacked vertically one above the other. The holding device equipped with car tires in this way is attached to the top of the removed furnace base and inserted vertically upwards into the open furnace. The furnace bottom equipped in this way is then fastened in a manner known per se via quick fasteners, screw fasteners or the like. tightly closed. The base plate of the receiving device can also be designed at the same time as the furnace floor and can be inserted directly into the furnace and attached to it without further intermediate assembly.

A particular advantage of the old tire pyrolysis according to the invention is that after pyrolysis has been carried out and the pick-up device has been brought out into a removal station, the residues can be separated from one another in a simple manner. So the cradle by ind. Pivoted 30 ° to approx. 90 ° to the vertical, as a result of which the free-flowing pyrolysis carbon falls out of the receiving device, for example onto a conveyor belt, which can be accelerated or reinforced by at least gentle shaking. Left behind Steel wire scrap, which as a ring-shaped braid remains relatively clean on the pick-up rods and can be easily removed and removed from there. The removal can be carried out via a special comb device, which, for example, presses the steel fabric on each rod from above onto the base plate of the receiving device and possibly shakes it, after which it is compressed from the rod, at the same time crumbling off remaining carbon parts. This enables a clear, clean separation of the solid residues without great effort.

In the case of pyrolysis, for example of crushed, pourable plastic or organic bulk goods, the receiving device consists of one or more stackable receiving containers which are filled to a maximum of 90% of their height with material to be pyrolyzed. The at least 10% remaining clear height between the containers is used for hot air circulation, for which purpose the side walls of the containers can additionally be provided with openings, forming perforated containers. It makes sense to leave at least the respective container bottoms unperforated in order to prevent the pyrolysis carbon from trickling down to the base plate of the receiving device. Of course, the container walls can consist of grid material at least in their upper edge zones or other, known measures can be taken to optimize hot gas circulation. In any case, after the pyrolysis has ended and the container receiving device has been moved out of the oven and into the unloading station, which can of course also be a loading station at the same time, remove the containers accordingly from the receiving device and empty the solid pyrolysis residues from them. The empty containers can then be stacked again in a receiving device. In order to avoid undesirable carbon dust formation when pouring the pyrolysis soot out of the holding devices or from the base plate or from the containers, the pyrolysis carbon can be sucked off directly from the holding devices, that is to say from the device base plate or from the containers and in suitable recording or Transport containers are introduced.

According to the invention, it is furthermore advantageous if, when the pyrolysis furnace is heated, for example via a gas or oil burner, the hot gases generated in the helical hot air duct between the concentric furnace walls of the double-wall furnace, the hot air is conducted helically from bottom to top, then drawn off at the top of the furnace and the exhaust air heat is economically used in a known manner. This hot exhaust gas can then be returned to the furnace, etc. in its lower zone, or hot air can be introduced from a heat exchanger. With this, the furnace can be kept at an optimal temperature even when the burner is temporarily switched off, for example during open times of the furnace when inserting or removing the receiving device with material to be pyrolyzed, so that the furnace quickly returns to an optimal pyrolysis temperature of 450 ° -550 ° C can be brought. A very energetically economical and economical process control is hereby possible according to the invention. It is advantageous if the helical transverse walls of the spiral channel are only welded to the inner wall of the furnace, while they are thermally insulated from the outer wall. This avoids the formation of a temperature bridge through which valuable heat is dissipated to the outside instead of the inside. In addition, the furnace walls are surrounded on the outside with a thermally insulated jacket in a manner known per se. The furnace walls near the burner are also lined with chamotte to protect them from all too great thermal influences.

In order to achieve a particularly high thermal efficiency, radially inwardly extending heat release plates are provided in the interior of the furnace, which line the entire interior of the furnace as annular ribs. Furthermore, to facilitate work and at the same time to reinforce the ribs, at least three or more vertical insertion rails spaced evenly apart are attached to the inside of the ribs. These cooperate with the pick-up devices, also uniformly distributed over the circumference and arranged in the same number of insertion rods.

According to the invention, the carbon obtained by the pyrolysis described above (pyrolysis soot) can be used in extremely valuable ways.

The pyrolysis carbon can be used in conjunction with low cement proportions for highly heat-insulating, thus thermally insulating building materials such as slabs or bricks. Pyrolysis soot can also be used in connection with gypsum or refractory cement for fire protection elements, for example for fire protection panels and fire or heat shields. For this purpose, for example, three parts of plastic or carbon are mixed with one part of gypsum, of course with the addition of water and processed into a plate, for example. Experiments have shown that an approximately 1.5 cm thick plate can be made glowing hot at the top and at the same time held by hand at the bottom, without the effect of heat on the hand.

A particular use of pyrolysis carbon (soot) is the use according to the invention as a fire extinguishing agent, e.g. to extinguish burning oil. If carbon dust is sprinkled on burning oil, then first the air-oxygen supply to the oil layer is cut off and the oil is also sucked up by the highly absorbent carbon (adsorption), so that the fire is extinguished by the carbon, which is no longer burning itself . This can extinguish a burning oil slick or even a pan fire in the kitchen, very efficiently and relatively quickly.

Finally, according to the invention, pyrolysis carbon can be used to prevent or contain the oil spill known to be so devastating, for example after an oil tanker accident. Here the ability of carbon is used to absorb large amounts of oil and at the same time not to be wettable with water, which means that the carbon always floats on the water surface. For example, an oil slick that spreads out after a tanker accident is sprinkled with the appropriate amount of carbon, after which the carbon carpet soaked in oil, elongation is considerably smaller than the previous oil slick, is skimmed off. It can then be fed to another pyrolysis, for example by the plant according to the invention, as a result of which oil and carbon are separated again.

According to the invention, as already mentioned, high-quality vegetable oils, such as spruce needle oil or medicinal vegetable oils, can be produced which can be used in medicine and / or cosmetics.

It is also possible to pyrolyze animal bodies according to the invention, which likewise gives an oil and "animal charcoal". This eliminates the traditional animal body combustion.

The invention is explained in more detail below on the basis of an exemplary embodiment with reference to the drawing.

Show it:

Fig. 1: a schematic representation in vertical

Section of a pyrolysis furnace according to the invention in the open state below, without base plate,

2: a side view of a receiving device for pyrolysing old tires, in a design firmly connected to an exchangeable furnace base plate, Fig. 3: a view according to arrow III of Fig. 2, the

Illustrating order of used tires on the cradle, and

Fig. 4: a side view of a receiving device with receptacles for rubble to be pyrolyzed well, in execution for interchangeable attachment to a pyrolysis furnace base plate.

As can be seen from the drawing, the plant according to the invention for pyrolyzing hydrocarbonaceous material consists of a pyrolysis furnace 1. Its double-walled, essentially bell-shaped furnace wall 2 consists of an outer wall 3 with an inner wall 4 constantly spaced therebetween, one of which is helical Arranged from bottom to top leading transverse radial wall 5, which forms a spiral channel 6, for screwing up from bottom to top in the double wall of the hot air generated by a burner 7. In the burner opening 8, a slide valve 9 is provided, via which the introduction of the hot air into the spiral duct 6 is controlled. On its upper side, the furnace wall is tapered in diameter to form a dome, from which some discharge pipes are arranged to lead away.

Thus, an exhaust pipe 11 leading upwards is provided, via which the hot air originating from the burner 7 and transported upward via the spiral duct 6 is discharged through a chimney or brought to a heat exchanger or other use of warm air. This exhaust pipe 11 can be closed if necessary via a valve 12. From the interior of the dome 10, a pipe 14, which can be controlled via a valve 13, leads radially away and is used for heat extraction for a heat exchanger or for a heat container, hot air coming from these then, for example, via a supply pipe 16 provided with a valve 15 on the underside of the oven the spiral channel 6 is fed.

A discharge pipe 20 leads vertically from the dome 10, essentially in the middle, with which the pyrolysis gases collecting in the dome are discharged. The discharge tube consists of a short vertical tube part 17 which merges into a tube part 18 which is inclined slightly downwards to the horizontal and which has a somewhat larger cross section than that of the tube part 17. A condensate line 19 leads away from the pipe part 18, a temperature-controlled electrovalve 21 being led either to the line 19 or to the pipe part 18 carrying gas and oil vapors. The pipe part 18 in turn leads either via the oil line 22 into a cooling coil 23 which is passed through a cooling water tank 24 and opens into an oil collecting tank 25 from which the oil collected can be discharged via a discharge pipe 26.

The pipe part 18 can, however, also merge into a gas pipeline 27, which can be accomplished via a rotary switching part 28. Pyrolysis gas, which can subsequently be fed as fuel gas, for example to the burner 7, is discharged into this gas pipeline 27, in particular in the case of a pyrolysis process control for gas generation, for example of wood gas. It is the same or in a similar manner to the line 22, for example via a cooling coil and cooling container, can be cooled. It should be noted that an essentially unpressurized, closed gas cycle can take place, with no gas escaping to the outside.

Regarding the radial wall 5 forming the spiral channel 6, it should be noted that this is only on the inner wall 4 of the furnace by welding or the like. is attached, while it is only sealed to the outer wall 3 in a thermally insulated manner, in order to avoid unnecessary dissipation of temperature to the outside. The furnace is also provided on the outside with an insulation jacket 30, while on the inner wall 4 radially inwardly pointing ribs 31 are provided, which serve for better heat transfer into the furnace interior 32.

At least three vertical insertion rails 33 are attached to the inside of the ribs 31 in a uniform circumferential division and form an insertion slope 34 on their lower side. The furnace is closed at the bottom by a flange 37 on which fasteners 38 in the form of screws or the like. for an oven bottom to be described in connection with the other figures.

As can be seen from FIG. 2, according to the invention a first holding device 40 essentially consists of a base plate 41 on which a plurality of holding rods 42 are fastened for holding used tires 44 stacked vertically one on top of the other. In this embodiment, four receiving rods are provided. Their arrangement on the base plate 41 depends on the size of the old tires and the pyrolysis furnace or the base plate 41 of the receiving device 40.

On the outer periphery of the base plate 41 there are further insertion rods 43 which cooperate with the insertion rails 33 of the pyrolysis furnace 1 when inserting the receiving device 40 into the pyrolysis furnace and help prevent damage to the receiving device and / or the furnace inner lining. The base plate 41 is fastened to a base plate 45 via screw fastening elements 46, which in turn has a sealing fastening flange 47. The mounting flange, when the receptacle 40 is inserted and fastened into the pyrolysis furnace 1, cooperates with the flange part 37 of the pyrolysis furnace for sealing fastening, after which the receptacle 40 is fastened via the base plate 45 by the interaction of fastening eyes 48 with the fastening elements 38 of the furnace. On the underside of the base plate 45, stack receptacles 49 are provided, via which the pick-up device 40 is handled. That A forklift engages in the stack receptacles 49, the fastening elements 38, 48 are released, the forklift, which carries the receiving device 40 over its base plate 45, lowers it vertically until it has moved out of the oven and moves it to an unloading station , after which he brings a newly loaded holding device to the furnace and vertically lifts or guides it into the furnace.

The receiving device 50 shown in FIG. 4 also has a base plate 41 on the screw fastening elements 46 for fastening to a base plate, not shown here, similar to that shown in FIG. 2. Here too, insertion rods 43 are provided on the base plate 41, which interact with the insertion rails 33 during insertion and removal. Receptacles 51 are stacked vertically one above the other on the base plate 41 and are supported against one another by stack edges 53 provided in each case. Of course, it can also be interpreted in such a way that additional support for the receptacle 51 takes place via the insertion rods 43. Bulk material 54 is introduced into the receptacle 51 and only so far that a distance 55 remains open to the upper container edge or to the receptacle 51 stacked above it, which serves for rapid, unhindered heat exchange. In addition, perforations are provided in the vertical walls 52 of the receptacle 51, provided that it is not a bulk material that could trickle out laterally through these wall holes.

B E Z U G S Z E I C H E N L I S T E

1. Pyrolysis furnace 29th

2. Furnace wall 30. Insulating jacket

3. Outer wall 31. Ribs

4. Inner wall 32. Interior of the furnace

5. Radial wall 33. Entry rails

6. Spiral channel 34. Entry slope

7. burner 35. -

8th burner channel 36

9. Valve 37

10. Dome 38. Fastener

11. Exhaust pipe 39. -

12. Valve 40. Cradle

13.Valve tube 41

14. Pipeline 42

15. Valve 43. insertion rod

16. Feed tube 44. Old tires

17. Pipe part 45. Base plate

18. Pipe part 46. Fastening element

19. Condensate line 47. Mounting flange

20. Discharge tube 48. Fastening eyes

21. Electro valve 49

22. Oil line 50. Holding device

23. Cooling coil 51. Receptacle

24. Cooling water tank 52nd wall

25. Oil collecting container 53. Stack edges

26. Drain pipe 54. Bulk

27. Gas pipeline 55. Distance

28. Switching part

Claims

PATENT CLAIMS 1. Process for the pyrolysis of hydrocarbon-containing waste products, in particular used tires, in which a) the material to be pyrolyzed is placed outside of the furnace (1) in a loading station in or on a receiving device (40, 50), b) then the receiving device (40, 50) is introduced from below into a pyrolysis oven open at the bottom, the oven (1) tightly closing at the same time, c) after which the furnace (1) is heated via a burner (7) to the pyrolysis temperature of approx. 500 ° C. and the pyrolysis is carried out, d) after the pyrolysis has been completed, the holding device (40, 50) is lowered removed and brought into an unloading station, where the residues are discharged, e) and another receiving device loaded with material to be pyrolyzed is brought from the loading station to the furnace and is inserted therein. 2. The method according to claim 1, characterized in that to keep the furnace (1) warm during its unloading and loading from below, the furnace is kept warm with the aid of its own hot exhaust air or heat exchanger air. 3. The method according to claim 1, characterized in that when pyrolyzing old tires (44), the tires (44) are stacked on at least one upwardly facing vertical receiving rod (42) (spacer rods) of the receiving device (40) . 4. The method according to claim 1, characterized in that when pyrolyzing agricultural and forestry products or bulk material (54) these are introduced into vertically stacked, easily removable receptacles (51). 5. The method according to claim 3, characterized in that the receiving device (40, 42) is tilted and shaken in the unloading station by 30 ° to 90 ° to the vertical, for removing the free-flowing pyrolysis solid residues, after which the on the receiving rods ( 42) attached remaining metal components, are deducted from these. 6. The method according to claim 4, characterized in that in the unloading station, the receptacles (50, 51) are removed vertically from the receiving device (56) and the pyrolysis solid residues contained therein are applied by appropriate dumping and shaking or suction, after which load them again and insert them into a holding device (50). 7. Plant for performing the method claims 1 to 6, consisting of a pyrolysis furnace (1) which is an externally heated double-wall furnace with helical cross walls (5) leading from the bottom to the top, which form a spiral channel (6) for the hot air, - The furnace has a vertically lowerable bottom (45) and is designed to be loaded and unloaded vertically from below. 8. Plant according to claim 7, characterized in that at least one material receiving device (40, 50) is provided which can be fastened on the upper side of the vertically movable bottom (45) or is part of the bottom, thus at the same time the closure bottom plate ( 45) of the furnace (1). 9. Plant according to claim 8, characterized in that for a furnace several furnace floors (45, 47) are provided, each with a fixedly arranged receiving device for the material to be pyrolyzed. 10. Plant according to claim 8, characterized in that only one furnace floor (45, 47) and several separate, cooperating with this receiving devices (40, 50) are provided, which on the base plate (45) of the furnace floor via screws, quickly are designed to be fastened. 11. Plant according to claim 8, characterized in that for the pyrolysis of old tires (44), the receiving device (40) on a base plate (41) attached, vertically projecting receiving rods (42) for stacking the rows of tires (44). 12. Plant according to claim 11, characterized in that for pyrolysing crushed, pourable material, at least a stackable receptacle (41) with lateral wall openings are provided as a perforated plate container. 13. Installation according to claim 7, characterized in that for the safe insertion of the receiving devices (40, 50) at least three near the outer circumference on the base plate (41) vertically arranged insertion rods (43) are provided, while in the pyrolysis furnace ( 1) vertical insertion rails (33), radially spaced from the furnace inner wall (4), with opening-side insertion bevels (34) are arranged. 14. Plant according to claim 7, characterized in that the pyrolysis double-wall furnace (1) can be heated electrically or via oil or gas burners (7) from the outside and in that the cylindrical furnace inner wall (4) points radially inwards up to the insertion rails (33) reaching heat release plates or jet fins (31) is equipped. 15. Plant according to claim 7, characterized in that the upper hot air or exhaust gas - pipe (11) and / or the line from a heat exchanger to an insertion or feed pipe (16) at the lower end of the furnace (1) is guided. 16. Plant according to claim 7, characterized in that the helical transverse walls (5) of the helical channel (6) are only welded to the furnace inner wall (4) while they are thermally insulated with the furnace outer wall (3), and that the furnace walls (3, 4) in the vicinity of the burner (7) are lined with chamotte and the furnace has a thermally insulating jacket (30) on the outside as a whole. 17. Use of pyrolysis carbon, produced by the method and system of the preceding claims, in conjunction with a low proportion of cement for highly heat-insulating building materials. 18. Use of pyrolysis carbon in combination with gypsum or refractory cement for fire protection elements, such as fire protection plates, fire or heat shields. 19. Use of pyrolysis carbon according to claim 18, characterized in that a mixing ratio of three parts of carbon with one part of gypsum is used. 20. Use of pyrolysis carbon as a fire extinguishing agent, e.g. for extinguishing burning oil, large fires, forest and meadow fires, fires on water. 21. Use of pyrolysis carbon to prevent oil spills, especially after an oil tanker accident, carbon being scattered onto the oil slick and the carbon carpet soaked in oil, floating on the water and drastically reduced in area, and exhausted by subsequent pyrolysis the separation into oil and carbon is carried out again.